Refrigerating apparatus



Oct. 1s, 193s. A, A. MCCORMACK 2,133,358

REFRIGERATING APPARATUS Filed Aug. 29, 1934 2 Sheets-Sheet l v LAM ,415x A. @SCORM/mx y wmymfz I dered recesses S6 and 10 by expansible clamping rings '15. v

In operation; the motor I6 may be energized under the control of a suitable automatic switch (not shown) and causes rotation of the shaft I2 which in turn actuates the impeller 36, causing it to revolve in the body member 30 without rotating. The motion of the impeller 36 causes Withdrawal of refrigerant uid from the evaporator 26 through the suction aperture 52 and compresses the uid delivering it through the exhaust aperture 5B as is well known in compressors of the general type described. The flexible resilient facing member 5B is tightly pressed against the impeller 36 by the springs 48 and provides a gas tight seal between the compression space 40 and the suction space 42 due to its resilience which permits the impeller 3&5 to deform the surface of the facing member 50, causing a wide area of contact. Also, due to the resilience of the facing member 50,-it conforms tc any slight irregularities which may be present in the .contour of the impeller 3G, thus materially improving the tightness of the seal at that point and maintaining this condition throughout' the useful life of the compressor. The sealing sleeves 'I6 being flexible follow the revolving movement of the impeller 3&3 and being impervious provide a hermetic seal for the compression space Within the body member 30. Inasmuch as the exible resilient material of the sealing members 50 and 'id is not deteriorated in the presence `of the common refrigerants and lubricants, the compressor operates eiciently and without substantial leakage over long periods of use. particularly useful in a refrigerating system employing as a refrigerant a iuorine derivative of a hydrocarbon, for example dichorodiuoromethane and as a lubricant a mineral oil wherein great diculty is encountered in preventing leakage across metal to metal contacts and wherein the use of rubber is prevented by the rapid deterioration thereof caused by the refrigerant and lubricant.

It will thus be seen that there has been provided a rotary compressor in which a gas tight seal will be maintained satisfactorily throughout a long period of useful life, not only at the surface between the divider block and the impeller,

` but also for the surface between the impeller and the end walls of the cylinder within which it revolves. The latter seal is hermetic in that there are 11o/'running joints involved in this construction, and it, furthermore, permits actuation of the compressor by means of a shaft which is external to the compression space of the compressor. In other Words, the present invention provides the advantages of a hermetically sealed compressor unit which include Ythe elimination of stuing boxes or other running joints for shaft seals and the consequent avoidance of leakage of refrigerant, and yet avoids the disadvantage of This feature is arsenaler having tolocate the moto within the hermetically sealed portion of the compressor. Furthermore, the invention provides a compressor eminently suited for the eflicient compression of refrigerants comprising fluorine derivatives of hydrocarbons.

While thedfrm of embodiment of the invenpiston means eccentrically within the cylinder for pumping fluids into and out of the pumping chamber, and a plurality of sleeves formed of gasy tight flexible material impervious to said fluids,I each of said sleeves having one end immovably connected to an end of said piston means and the other end immovably connected to the adjacent end Wall of the casing to provide a hermetic seal between both ends of said piston means and the casing and to secure said piston means against rotation.

2. A pump according to claim i, in which the sleeves are substantially the same in size and are symmetrically located to balance the fluid pressures upon the piston means.

3. A pump according to claim i, in which the end walls of the casing and the ends of the piston means are formed with cut-away portions to provide spaces surrounding said sleeves.

4. A pump including a casing having an annular wall forming a `cylinder and end walls therefor and having inlet and outlet ports, piston means fitting Within said walls to form va pumping chamber, the piston means being smallery in transverse section than the cylinder and having contact with one of said end walls in all operative positions of the piston means, means for revolving the piston means?` eccentrically within the cylinder for pumping uids into and out of thepumping chamber, and a sleeve formed of gas-tight material impervious to said pumping fluids, said sleeve having one end immovably connected to said one end wall and the other end immovably connected to the adjacent end of the piston means to provide a hermetic seal between said adjacent end of the piston means .and said one end wall of the casing and to secure the piston means against rotation, and said adjacent end of the piston means and said one end Wall of the casing being formed with cut-away portions to provide a space surrounding said sleeve.

LEX A. MCCORMACK. 

